1. Field of the Invention
This invention generally relates to compositions of structured lipids and phytosterol esters. These compositions are especially suitable for use as components having health and nutrition promotion characteristics. More particularly, the invention relates to structured lipids for use as edible oils in combination with phytosterol esters in a variety of applications for promoting health and nutrition enhancement for those applications, such as in products for consumption and/or use by living beings, especially humans.
2. Description of Related Art
Vegetable-based edible oil compositions long have been used in baking, frying and food dressing applications. Edible oil products provide taste, nutrition and anti-stick properties for any number of pan cooking, baking, dressing or similar types of uses and applications. Edible oil products of this general type include liquid oils, cooking oils, margarines, whipped spreads, tub margarines, shortenings, oils, sprayable compositions, salad dressings and the like. Edible oils also can be included in compositions administered to individuals in compositions that are not necessarily mainstream food products. Some can be directed to fine tuning nutritional input or addressing metabolism objectives. Traditional edible oil products, including those of the long chain variety, have been used in these types of applications.
In the health, nutrition and metabolism art, publications suggest the usefulness of phytosterols in oil-based compositions. References which are in this general field include St-Onge, et al., “Consumption of a Functional Oil Rich in Phytosterols and Medium-Chain Triglyceride Oil Improves Plasma Lipid Profiles In Men,” American Society for Nutritional Sciences, 0022-3166/03, (2003), Journal of Nutrition, Volume 133, pages 1815-1820, (2003) reports a study evaluating the effects of a combination of medium chain triglyceride oil, phytosterols and flaxseed oil on plasma lipid concentrations and LDL particle size. Another article discussing plant sterols or phytosterols is St-Onge, et al., “Phytosterols and Human Limpid Metabolism: Efficacy, Safety and Novel Foods,” Lipids, Volume 38, No. 4, pages 367-375, (April, 2003). This article reports on studies regarding cholesterol-lowering efficacy of plant sterols with a view toward greater use of phytosterols in heart health promotion.
Medium chain triglyceride (MCT) edible oils are known in the art including Seiden U.S. Pat. No. 5,288,512, Bertoli et al. U.S. Pat. No. 5,395,629, Hidaka U.S. Pat. No. 5,503,855 Takeuchi U.S. Patent Publication No. 2002/0001660, and Heydinger and Nakhasi, “Medium Chain Triacylglycerols, Journal of Food Lipids, Volume 3, pages 251-257 (1996). Additional articles concerning MCT art include the following. St-Onge, et al., “Medium-Chain Triglycerides Increase Energy Expenditure and Decrease Adiposity in Overweight Men,” Obesity Research, Volume 11, No. 3, (March, 2003) indicates that upper body adipose tissue in this study decreased using a functional oil blend of medium chain triglyceride oil, canola oil, flaxseed oil, coconut oil, and unesterified stanol/sterol mixture. St-Onge et al., “Greater Rise in Fat Oxidation With Medium Chain Triglyceride Consumption Relative to Long Chain Triglyceride is Associated With Lower Initial Body Weight and Greater Loss of Subcutaneous Adipose Tissue,” International Journal of Obesity, Volume 27, Pages 95-102 (2003) reports on a study to the effect that body weight decreased with medium chain triglyceride consumption when compared with long chain triglyceride consumption. These references, and each of the publications and patents noted throughout herein, are incorporated by reference hereinto.
Publications such as these define these medium chain triglyceride or medium chain triacylglycerol (MCT) compounds as being a class of lipids of glycerol ester fatty acids. MCTs are esters of glycerol with medium chain fatty acids of 6 to 12 carbon chain lengths. Sources typically are lauric oils. Coconut and palm kernel oils contain significant quantities of C8 (caprylic) and C10 (capric) chains. Often, isolated fractions of C8 and C10 acids contain small amounts of C6 and C12 acids as well. Generally, MCT esters are saturated. Accordingly, the primary components of MCT edible oils have C8:0 and C10:0 fatty acid chains.
References of Forbes Medi-Tech Inc also discuss phytosterol compositions. Stewart et al. U.S. Pat. No. 6,087,353 describes phytosterol compositions which are esterified and subsequently hydrogenated. These are said to be suitable for use alone or for incorporation into foods, beverages, pharmaceuticals, nutraceuticals, and the like. Zerawistowski et al., International Publication No. WO 01/91587 describes oil compositions comprising short, medium and long chain triglycerides and the use thereof in reducing weight gain. Zawistowski et al., also discusses phytosterols, which incorporates phytostanols as noted therein. These phytochemicals are presently believed to have an ability to decrease serum cholesterol levels when fed to a number of mammalian species, including humans. Zawistowski et al. indicates that the relationship between cholesterol and phytosterol is apparently due in part to similarities in the respective cholesterol and phytosterol chemical structures. The mechanism set forth in references such as these is that phytosterols displace cholesterol from the micellar phase to reduce its absorption or compete with cholesterol in its absorption process. Esterification of triglycerides is generally referenced in Zawistowki et al., including referring to interesterifying short, medium and long chain triglycerides for forming described chain residues.
Interesterification is a known reaction of triacylglycerol structures whereby individual fatty acid structures at positions of the triglyceride being interesterified are interchanged on the glycerol moiety. This is at times referred to or recognized as a randomization wherein fatty acid moieties from one glycerol component of a triacylglycerol are exchanged with those of a glycerol component of another triacylglycerol. This results in triacylglycerol structures which have interchanged fatty acid moieties that vary from glycerol structure to glycerol structure. Art in this area includes Pelloso et al. U.S. Pat. No. 5,434,278, Doucet U.S. Pat. No. 5,908,655, Cherwin et al. U.S. Pat. No. 6,124,486 and Liu et al. U.S. Pat. No. 6,238,926.
The art of interesterification has developed to form, for example, triglyceride compositions which provide certain melt profiles that can be of interest in certain applications. Generally these are recognized herein as “structured lipids” in order to help distinguish the interesterified products from other products which are physical blends of the same components but that have not been subjected to interesterification.
Heretofore, it has not been appreciated that the combination of interesterification technology and MCT technology and phytosterol technology would be especially advantageously applied to the task of improving health, nutrition and metabolism promoting compositions having a substantial edible oil content. An especially important problem in this regard, which is addressed by interesterified components according to the invention, is to provide a composition that has health, nutrition and improved metabolism promoting characteristics while simultaneously exhibiting very acceptable properties for combining with and/or adding into products for ingestion by and/or treatment of individuals. Most especially, it has been found that the compositions of this invention are substantially equal, or improved, substitutes for conventional edible oils used in making and/or formulating food products.